Attachment theory states that a strong emotional and physical attachment to at least one primary caregiver is critical to personal development. John Bowlby first coined the term as a result of his studies involving the developmental psychology of children from various backgrounds. Further research was conducted by Mary Ainsworth who discovered various attachment styles. More recently these styles have been associated with trauma responses and their long term impact on healthy functioning. The clinician that is informed by attachment theory will understand how attachment styles impact relationships and work with the client to unwind from early childhood trauma related to attachment.